docs: record the audit backlog, replacing the lost tracker database

[Ugbot]

The 2026-07-25 audit produced 44 tickets in a SQLite tracker under the home directory. That database was destroyed on 2026-07-26 by an unrelated incident that wiped most of ~. The eleven epics survived as issues #1–#11; the thirty-three sub-tasks existed only in the database.

docs/audit-backlog.md is now the source of truth for them — committed, so it survives any future machine loss.

What it preserves

• All 44 tickets, each with the original file:line citations and the measured numbers, so nothing has to be rediscovered.
• The epic → issue map with each task's tracker uid, recovered from the markers in the issue bodies. A rebuilt tracker can reuse those uids, so the existing issue markers keep resolving instead of renumbering.
• The measured baseline (770 main-module tests, 922 in CI, per-surface counts) and the four ground-rule decisions that shaped the list — ship scope, the paradigm bar, the publishing target, and Java 21.
• Two tickets already closed, marked as such: AGS-9 (f39e6a1) and AGS-22 (9731fdc).

Corrections to the audit, recorded deliberately

Six findings were wrong on first pass and are documented as such so they are not re-filed as defects:

• The langchain4j and a2a-java BOMs resolve fine — the offline failure was the unpublished jagentic-core.
• The shaded-jar setup is correct (thin main artifact + classified -uber), not an anti-pattern.
• examples-bin/ is intentionally tracked scripts, not committed build output.
• A mistyped removeEldestEntry does not compile as a silent overload — javac rejects the erasure clash, so the compiler guards that bug, not a test.
• tasks.uid already existed in the tracker with deterministic re-keying on collision; the real defect was publishing the mutable key in issue markers.
• ToolExecutorRegistry.register(...) does exist; only ToolRegistry lacks it.

Verification

Docs-only change, no code touched. Rebuilt on a freshly restored toolchain (JDK 21.0.12 + Maven 3.9.16 via sdkman, from a completely empty ~/.m2): jagentic-core 95 tests pass, main module rebuild green. CI will confirm on this PR.

🤖 Generated with Claude Code